Sketch Piston - playing music

This device lets people play music by drawing lines on the screen with their fingers and then tapping the screen to drop a ball onto the lines.

The canvas is the world, and the lines drawn affect the world, which is created as sounds are played and balls and characters bounce around. The musical scale played on a line depends on the height where it is drawn. The people who are there play music together by drawing lines and tapping the screen to make balls appear.